Insufficient roof ventilation can result in a prolonged interface between still moist air and a colder surface. Moisture condensation on the colder surface occurs when these conditions are present. The condensed moisture often spots and damages ceilings. In more severe cases structural members such as joists and studs are continually damp and become unsound. Buildings with insufficiently ventilated roofs also tend to be warmer in summer months due to the presence of solar-heated air trapped within. These buildings are more expensive to maintain at comfortable temperatures than if the roofs thereof were adequately ventilated. When adequate ventilation occurs, air is kept in motion by being circulated from the outside the roof, through the attic and out through vents often placed near the ridge. This ventilation is necessary in order to prevent accumulation of hot air or condensed moisture. Various products have been developed to provide forms of ventilation. These products either provide separate ventilation structures or are themselves building materials with ventilating properties.
One particular type of design calls for a gap or slot to be cut into the decking at or proximate the peak of a roof. A ventilated cover is disposed over the gap and is attached to the roof along each side of its peak. Ventilation is provided by air passages within the ventilated cover which extends downwardly from the peak toward the eaves. U.S. Pat. No. 4,803,813 to Fiterman and U.S. Pat. Nos. 5,094,041 and 5,331,783 to Kasner et al., describe various methods of scoring, folding, and routing blanks of corrugated plastic sheet material to form foldable roof vents, as well as methods for installation and use of these vents. These folded roof ventilators were traditionally made and sold in lengths of approximately four feet. A hinged double-length roof vent, disclosed in U.S. Pat. No. 5,304,095 to Morris, enhanced the shipping and installation of such roof vents.
Other types of roof covering products such as shingles, tar paper, and some roof ventilation products fabricated from woven fiber or other materials are distributed in rolled form. Distribution in rolled form permits longer lengths of the products to be shipped and installed. Moreover, installation of these rolled products eliminates or reduces some potentially undesirable features such as frequent seams and gaps.
U.S. Pat. No. 5,651,734 discloses a multi-layer ridge cap roof ventilator. The ventilator is fabricated from double-faced corrugated plastic sheet material and includes two opposing vents. After fabrication, the plastic sheet material is rolled into a spiral configuration, then secured in the spiral by bands for shipping. Upon arrival at an installation site, the roll is transported to the roof, unrolled, and the scored panels are sequentially folded to form the opposing vent parts. The finished ventilator is then secured to the roof.
Those skilled in the art will appreciate that it has heretofore been required to select between the advantages of assembled multi-layered corrugated plastic roof ventilators which cannot be rolled and rolled roofing products which also fail to provide the advantages of a multi-layered corrugated plastic product. Moreover, the former choice often requires additional steps to be taken during installation to convert a rolled and scored blank of double-faced corrugated plastic sheet material into an assembled multi-layer roof ventilator.
Those skilled in the art will appreciate yet other improved features in roof vents made of corrugated materials. These products offer economic and efficient features such as more efficient shipping, handling and storage. These products also offer enhanced features which reduce the time and effort necessary for installation.